| 摘要 |
PROBLEM TO BE SOLVED: To prevent cooling operation time from being extended in a vacuum cooling apparatus for reducing pressure in a cooling pool by a dry type vacuum pump.SOLUTION: The vacuum cooling apparatus configured to cool an object to be cooled by evacuating the inside of a cooling pool, includes: a cooling pool 2 for accommodating the object to be cooled; a vacuum pump 1 for sucking air from the cooling pool; a pressure detection device 7 for detecting pressure in the cooling pool; a vacuum pump dry valve 4 for sending outside air to the vacuum pump; and a vacuum valve 6 for preventing air sucked from the vacuum pump dry valve from being sent to the cooling pool. In the vacuum cooling apparatus, pressure P1 in the cooling pool at the start of cooling operation and pressure P2 in the cooling pool after the lapse of predetermined time from the cooling operation start are detected, an assumed pressure value in the cooling pool during cooling operation is calculated from the pressures P1 and P2, and when the pressure in the cooling pool during the cooling operation is higher than the assumed pressure value, cooling operation is stopped, and dry operation for actuating the vacuum pump while supplying outside air to the vacuum pump through the vacuum pump dry valve is performed. |
